i definitely agree with not letting the surf purists ruin it for you. i have typically ridden only surfboards for the last 6 years but in the last couple months my boards have been getting shorter and shorter because i wanna try some different moves in the waves that surfboards just don't allow you to do well. this is my latest little project. only 127cm long

all the boards i make are reshaped out of old surfboards that have snapped noses/tails and/or delam and this board came in particularly messed up so i had no choice but to cut it down shorter than average. still unsure what the end result will be. the board still has lots of work to do but hopefully i'll get it done before the next solid breeze.
it has quite a lot of rocker. the fin setup (may change) will be two larger fins on the outside tail and three smaller fins, one in the center and two at the nose. footpads, it will definitely be setup mutant style for better snaps on the wave. also i am adding balsa wood inserts to the fin areas for extra strength.
not sure if this helps with ideas but just give it a go at making your own. like plummet said, there is no better feeling than riding a great board you have shaped yourself.